This invention pertains to an improved poison bait formulation for control of German cockroaches [Blattella germanica (L.)]. More particularly, this invention relates to improved insecticide, bait compositions containing high levels of fructose and very low levels of glucose for the control of German cockroach strains.
Heretofore there have been a large number of insecticide compositions. Most of them are based on chemicals which are either capable of instant and delayed killing action. These prior poison baits contain various materials as food attractants. These food attractants used in compositions include various sweetening agents, together with the toxicant. The prior art describes insecticide bait compositions containing a very general array of sugars and sweeteners as attractants for cockroach control, without regard to diversity of feeding preferences as displayed by field cockroach strains.
For example, U.S. Pat. No. 4,386,071 relates to an insecticide natural bait composition which includes, in a broad sense, sugar or sugar substitute. Similarly, U.S. Pat. No. 4,845,103 relates to an insecticide bait composition for the control of cockroaches in which the food attractant system comprises various ingredients, including a mixture of liquid food, for example, molasses, corn syrup, maple syrup, honey.
U.S. Pat. No. 4,889,710 relates to a stable aerosol foam insecticide bait composition which includes as an attractant to facilitate consumption by the crawling insects, sugars or a sugar composition.
U.S. Pat. No. 4,985,413 relates to poison bait for control of insects, particularly cockroaches, wherein the bait contains a saccharide as a component in amounts of 0.1-10% by weight and 10-40% by weight based on the total weight of the composition. Examples of saccharide in the '413 patent are sucrose, glucose, d-fructose, lactose, black sugar, brown sugar, soft brown sugar, etc. Among the preferred sugars mentioned in the '413 patent are black sugar, brown sugar and soft brown sugar. The content of the saccharide is normally preferred between 10-40% by weight.
Without regard for the toxicant in the instant bait composition, it has been found that bait compositions having ultra high fructose to glucose ratios are more efficacious than those with lower fructose to glucose ratios. More particularly, it has been found that improved consumption performance of cockroach baits by field-collected cockroaches, has been found with bait compositions containing fructose to glucose ratios in excess of about 9:1, respectively. When fructose to glucose ratios are less than 9:1, feeding inhibition has been observed. Therefore by "ultra high" is meant a ratio of fructose to glucose in no less than 9:1 to about 10:0. Preferably, about 40% by weight of the total formulation is fructose.
A preferred embodiment of this invention are bait compositions having ultra high fructose content within the definition herein defined and a nonrepellent binder and from about 0.005% to about 1.0% of a cockroach effective toxic insecticide compound. Preferably the cockroach insecticide compound is an avermectin.
More preferably, the present invention provides such an insecticide--bait composition containing ultra high ratio levels fructose to glucose in the range of from 9:1 to 10:0, respectively, about 40% by weight of the total formulation is fructose and about 0.005% to about 1.0% of an avermectin insecticide. Most preferably, this insecticide--bait composition contains from about 0.01 % to about 0.5% of an avermectin insecticide.
Therefore, as the result of extensive studies with regard to cockroach bait containing very general arrays of sugars and sweeteners as attractants or feeding stimulants, it has been discovered that in many strains of the German cockroach [Blattella germanica (L.)], feeding is inhibited by moderate to high glucose levels. Conversely, feeding of these cockroach strains is stimulated by high or ultra high levels of fructose. The preferred bait compositions of the instant invention relate to insecticide bait compositions for insect control which contain a ratio of fructose to glucose of no less that about 9:1 and as great as about 10:0.
It is, therefore, the primary object of the present invention to prepare a roach bait composition which is highly effective, yet convenient to use.
It is a further object of the present invention to provide a roach bait which is especially attractive to roaches.
It is still a further object of the present invention to provide a roach bait composition which has no repellency characteristics and which is more attractive to the roaches than otherwise normal known bait formulations.
It is still a further object of the present invention to provide a roach bait which exhibits preferred consumption over prior bait compositions having a general array of sugars and sweeteners as attractants for the roaches.